A randomized double blind trial of valacyclovir hydrochloride (VACU) cytomegalovirus (CMV), end organ disease in patients with advanced HIV infection (<100 CD4 lymphocytes) the data and safety monitoring board (DSMB) of NIAID's division of AIDS met on 2-6-95 and recommended that this study be stopped due to significantly higher mortality seen in the VACV treatment arm. Further analysis revealed an overall trend for earlier mortality in the VACV arm; longer time to confirmed CMV in the VACV arms and earlier permanent discontinuation from VACV and gastrointestinal intolerance in that arm.